Bypass installer .NET Framework Version Checks
While trying to install the Orthagonal Toolbox plugin for Visio I was presented with the error message "This setup required .net framework version 1.1.4322. Please install the .NET Framework and run the setup agian."
Strange thing is I already had .NET Framework 3.5 SP1 installed...
The easiest solution to get around the problem was to download the free Microsoft Orca msi editor (Google it if the link breaks), open up the msi installer file, navigate to Custom Actions on the left, and delete DIRCA_CheckFX and VSDCA_VsdLaunchConditions.
After this, it's just a matter of saving the msi and rerunning the installer again. This time it skips the .NET Framework version check but continues to run as all the necessary libraries are already installed.